RESEARCH ARTICLE

Iodine-assisted ultrafast growth of high-quality monolayer MoS₂ with sulfur-terminated edges

¹ Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute and Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China
² Institute of Functional Porous Materials, School of Materials Science and Engineering, Zhejiang Sci-Tech University, Hangzhou 310018, China
³ International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba 305-0044, Japan
⁴ Faculty of Materials Science and Engineering/Institute of Technology for Carbon Neutrality, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
⁵ Shenyang National Laboratory for Materials Sciences, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
⁶ Advanced Technology Institute, University of Surrey, Guildford, Surrey GU2 7XH, UK

^* Corresponding author (email: bilu.liu@sz.tsinghua.edu.cn)

Received: 19 January 2023
Revised: 22 February 2023
Accepted: 5 March 2023

Abstract

Two-dimensional (2D) semiconductors have attracted great attention to extend Moore’s law, which motivates the quest for fast growth of high-quality materials. However, taking MoS₂ as an example, current methods yield 2D MoS₂ with a low growth rate and poor quality with vacancy concentrations three to five orders of magnitude higher than silicon and other commercial semiconductors. Here, we develop a strategy of using an intermediate product of iodine as a transport agent to carry metal precursors efficiently for ultrafast growth of high-quality MoS₂. The grown MoS₂ has the lowest density of sulfur vacancies (~1.41×10¹² cm⁻²) reported so far and excellent electrical properties with high on/off current ratios of 10⁸ and carrier mobility of 175 cm² V⁻¹ s⁻¹. Theoretical calculations show that by incorporating iodine, the nucleation barrier of MoS₂ growth with sulfur-terminated edges reduces dramatically. The sufficient supply of precursor and low nucleation energy together boost the ultrafast growth of sub-millimeter MoS₂ domains within seconds. This work provides an effective method for the ultrafast growth of 2D semiconductors with high quality, which will promote their applications.